RE: [Barracuda-commit] CVS Update: Barracuda

Hi Jake!

(Once again, I'm going to move this conversation back to the Barracuda list,
just because I think people will benefit from it.)

Ok, I need to take the time here to understand exactly what your change does
here, so be patient with me if I'm a little slow on the uptake ;-)

I read your description of what you did, but I'm still a bit confused...

> concept of a "delegate runtime value". What this means is that
> the value of the parameter to be set is a runtime object rather
> than something that can be provided as a literal value in the
> configuration file. Currently, the only supported delegate

Do you mean by this that all you are doing is invoking a method on an
object? (rather than setting a static variable?)

Looking at your example in the Barracuda event-gateway.xml file, I see this:

    <dom-loader
factory="org.enhydra.barracuda.core.util.dom.XMLCDeferredParsingDOMFactory">
        <set-property name="servletContext" delegateRuntimeValue="true" />
    </dom-loader>

What exactly is this doing (ie. in terms of psuedo-code)? I'm guessing it
involves instantiating the XMLCDeferredParsingDOMFactory and then calling
setServletContext() on it, but I'm probably wrong about some of the
specifics.

To step back a level, what is the high level objective of this? It looks
like you are trying to
a) specify a pluggable implementation of the DOMLoader
b) make it possible for that DOMLoader to get a reference to the servlet
context

Can you confirm/correct my understanding of that? If I understand it
correctly, then I think there may be an easier way to do this, but I'll wait
to hear from you first before commenting further...

Christian
----------------------------------------------
Christian Cryder
Internet Architect, ATMReports.com
Project Chair, BarracudaMVC - http://barracudamvc.org
----------------------------------------------
"Coffee? I could quit anytime, just not today"


> -----Original Message-----
> From: Jacob Kjome [mailto:[email protected]]
> Sent: Wednesday, June 18, 2003 10:37 PM
> To: Christian Cryder
> Subject: Re: [Barracuda-commit] CVS Update: Barracuda
>
>
> Hi Christian,
>
>
>
> Log message:
>         <b>csc_061803.1</b> - Modified ObjectRepositoryAssembler
> to support the setting of
>         Shorts, Longs, Doubles and Floats in addition to the
> String, Boolean, and Integer
>         support that was already there. While I was at it I
> discovered that the previous
>         implementation only supported the setting of primitives,
> so I modified things so that
>         you can set both primitives and their first class counterparts.
>
>
>
> Might we want to add the notion of the "delegate runtime value"
> which I added to the DefaultApplicationAssembler?  Here is my
> comment from A_Changes_History about that....
>
> <quote>
> jrk_20030529.1 - Updated handling of <set-property> and
> <constant> in DefaultApplicationAssembler to recognize the
> concept of a "delegate runtime value". What this means is that
> the value of the parameter to be set is a runtime object rather
> than something that can be provided as a literal value in the
> configuration file. Currently, the only supported delegate
> runtime value is a ServletContext object. The syntax of this new
> configuration option is...
>
>
>    <set-property name="servletContext"
> delegateRuntimeValue="true"/>
>
>
>
> Obviously this assumes that the class this property is to act
> upon have either a public "setServletContext()" method or a
> public "servletContext" field.
>
> Also updated XMLCDeferredParsingDOMFactory to take advantage of
> this feature, the reason being that it needs to read context init
> parameters to provide extra optional information to the
> DeferredParsingFactory which the DeferredParsingDOMFactory backs.
> Also modified it to create the DeferredParsingFactory once
> instead of every time DOMFactory#getInstance() is called. This
> should provide a slight performance improvement.
> </quote>
>
>
> So, this just says "I, the configuration file writer, delegate
> the responsibility of the setting of a runtime object to a method
> that I specify because I cannot possibly script this value in a
> configuration file."
>
> does that make sense?  Of course, only certain specified
> "delegate runtime values" would be supported, but you can look at
> DefaultApplicationAssembler to see how I implemented this for
> methods taking the current runtime ServletContext object.  It
> works perfectly and allowed me to duplicate the web.xml
> configuration functionality of XMLCContext in the
> XMLCDeferredParsingDOMFactory.
>
>
> Jake